Basic oxygen furnace construction



Jan. 30, 1968 N. T. CRICHTON 3,366,377

BASIC OXYGEN FURNACE CONSTRUCTION Filed Jan. 10, 196 6 INVENTOR. NEIL T. CR\CHTON A T TOR/V5 Y United States Patent Ofilice Patented Jan. 30, 1968 3,366,377 BASIC OXYGEN FURNACE CQNSTRUCTION Neil T. Crichton, Detroit, Mich, assignor to Hal-bison- Walker Refractories Company, a Division of Dresser Industries, Incorporated, Pittsburgh, Pa.

Filed Jan. 10, 1966, Ser. No. 519,686 6 Claims. (Cl. 266-35) The present invention relates to furnace structure for the oxygen steelmaking process. More particularly, this invention relates to the structure extending between, and in effect, linking, the furnace bottom and walls.

In the oxygen steelmaking process, which has been variously designated as the LD process, oxygen Bessemer process and the oxygen converter process, the furnace structure fundamentally consists of a metal shell having a refractory lining disposed therein. The lining for oxygen steel furnaces consists of an inner or working lining, and an exterior or tank lining, sometimes with an intermediate brick or rammed lining. The vessel is generally composed of three major zones, these three zones being the bottom zone, the barrel zone and the cone section zone. The bottom zone is generally dishshaped and of upwardly opening concave configuration. The barrel zone extends from the dish-shaped bottom, upwardly to the cone section zone. The cone section zone is of downwardly opening, truncated cross section configuration. Brick used are usually key or wedge shaped. Usually, the brick in all three zones of the working lining are laid so that the end surface of smallest area is exposed to the interior of said vessel. Similarly, the brick in the tank lining are laid so that an end surface (usually the larger end) is adjacent the metal shell.

The area in the vessel where the barrel zone brick meet the bottom zone brick is referred as the knuckle area. At this point of meeting, the top and bottom face surfaces of the brick in the bottom zone are inclined from the vertical axis of the vessel; whereas, the top and bottom face surfaces of the brick in the barrel zone are substantially horizontal. Thus, in this area, the interior end surfaces of the brick in the barrel zone are closely adjacent the brick in the bottom zone while the opposite end surfaces thereof are widely separated.

The knuckle area between the brick in the bottom and barrel zones has become a major point of weakness to the structural integrity of the vessel. Various types of refractory shapes have been proposed to fill the void between these divergent brick in the shell protective lining or tank lining to provide resistance to stresses and strains encountered in vessel operation. These stresses and strains are caused by the physical movement and manipulation of the vessel or furnace itself during the steelmaking operation, i.e., wide and cyclic variations in temperature, due to successive charging and tapping of heats of metal from the vessel, etc.

Current practice is to lay skewbrick on the inclined faces of the brick in the bottom zone to provide substantially horizontal surfaces at the barrel zone-knuckle area junction. The annular void is then presumably closed with standard brick of thicknesses ranging from 2 to 3" in increments utilizing two or three courses. However, annular voids up to resulted since the shell protective bottom and skewbrick could not be laid to a tolerance closer than 1 to 1 in relation to the terminal brick in the barrel zone.

Accordingly, it is among the objects of the present invention to provide an improved knuckle area construction at the tank lining for oxygen steelmaking vessels.

Another object of the invention is to provide a means for tightening the shell protective lining of a basic oxygen furnace.

Other objects of the invention will become apparent hereinafter.

In order to more fully understand the nature and scope of the invention, reference should be had to the following .detailed description and drawings in which:

FIG. 1 is an elevation view in partial section of a portion of a typical oxygen converter vessel, utilizing a construction according to the present invention.

FIGS. 2 and 3 are perspective views of the refractory shapes employed in the construction of FIG. 1.

Briefly, in accordance with the present invention, the improved construction in the knuckle area of a basic 'oxygen furnace shell protective lining consists of two contiguous courses of refractory brick. One course consists of key-wedge type brick in which the narrow end is laid adjacent the working lining.

The other course also consists of key-wedge type brick. However, these brick are laid so that the narrow end is adjacent the shell. The above combination of brick serves to firm the entire shell protective lining.

Key brick are shapes having six plane surfaces (two faces, two sides and two ends) in which two surfaces (the sides) are inclined toward each other and one of the end surfaces is narrower than the other.

Wedge brick are shapes having six plane surfaces (two faces, two sides and two ends) in which two surfaces (the faces) are inclined toward each other, and one end surface is narrower than the other.

Thus, the term key-wedge brick as used herein refers to brick having the properties of key brick and wedge brick simultaneously.

In a preferred embodiment, contiguous surfaces of brick pairs in each course contain depressions for reasons to be discussed later.

Referring to FIG. 1, there is shown a portion of a typical basic oxygen furnace 10 consisting of an outer metal shell 12, a shell protective brick lining 14 in contact with the inside surface of the shell and a brick working lining 16. The vessel is constructed of three major zones, the bottom zone 18, the barrel zone 20, and the cone section zone 22. The bottom zone is dish-shaped and of upwardly opening concave configuration. The brick 23, in the bottom zone, terminate in a knuckle area 24 with their face surfaces inclined from the vertical axis of the vessel. The barrel zone extends from the knuckle area upwardly to the cone section zone. The cone section zone, having a taphole 26, extends upwardly and terminates in the form of a mouth 23 at the top of the vessel. The cone section zone is of downwardly opening, generally truncated conical cross section configuration. The brick 23 and 29 in the tank lining are contoured through the knuckle 24 utilizing skewbrick 30. Because the close tolerances of brick alignment desired cannot be practically or economically attained, the key-wedge shapes 32 and 34 are utilized in accordance with the present invention.

Referring to FIGS. 2 and 3 each of the brick 32 and 34 contain opposing face surfaces 32a, 32b and 34a, 34b; opposing side surfaces 32c, 32d and 34c, 34d; and oppos ing end surfaces 32a, 32] and 34e, 34 One of the end surfaces 32s and 3412 is narrower than the other end of each brick. In addition, face surfaces 32a, 32b and 34a, 34b and side surfaces 32c, 32d and 34c, 34d are inclined toward each other.

Preferably, a face surface, 32a and 34a of each brick (the surfaces that are contiguous in service) are provided with depressions. In brick 32, which is the lowermost brick in each course when in service, desirably, contains hemispherical depressions 36. The upper brick 34 (which must be rotated in the vertical and horizontal directions for use directly on brick 32 as shown in FIG. 2) is provided with half round intersecting grooves 38 and 40.

These depressions in the brick provide a passageway for removal of excess mortar and a locking system between these brick when the mortar has dried.

In practice, the tank lining is laid as follows: The brick in the bottom zone are disposed in substantially the center of the zone for each course so that the face surfaces of the bottom brick are in alignment with the vertical axis of the vessel. The courses are then continued on the tank lining toward the curvature in the shell until the knuckle area is reached. At this point, the face surfaces of the brick are inclined from the vertical axis of the vessel. The knuckle area is built up with skewbrick until their face surfaces are in the horizontal axis of the vessel. The horizontal brick of the barrel zone are laid so that the face surfaces thereof are substantially parallel to the face surfaces of the skewbrick. The remainder of the barrel zone lining and the cone section zone lining is continued by stacking brick on brick.

There remains, at the knuckle area barrel zone junction, an annular space. A course of brick 32 are laid, on a face surface of the skewbrick, in a position shown in FIG. 2, so that the narrow end 32e is pointing away from the furnace shell. A mortar mixture is spread over the face surface 32a to the thickness desired. Then, the course of brick 34 are driven above so that the face surface 34a are adjacent the face surface 32a and the narrow ends 34c are pointed toward the shell. This procedure allows tightening of the entire tank lining.

It is intended that the foregoing description and drawing be construed as illustrative and not in limitation of the invention.

Having thus described the invention in detail and with sufiicient particularity as to enable those skilled in the art to practice it, what is desired to have protected by Letters Patent is .set forth in the following claims.

I claim:

1. In an oxygen converter vessel comprising a metal shell having a mouth at its top, a shell protective lining in contact with the inside surface thereof and a working lining, said vessel being composed of three major zones, the bottom zone, the barrel zone and the cone section zone, the bottom zone being generally dish-shaped and of upwardly opening concave configuration, the brick in said zone terminating in a knuckle area, said knuckle area being characterized by a curvature in the shell bridging the bottom and barrel zones, the barrel zone extending from the knuckle area upwardly to the cone section zone, the cone section zone being of downwardly opening truncated cross section configuration, the improvement comprising a shell protective lining knuckle area construction consisting of first and second brick having opposed face surfaces, side surfaces and end surfaces in which the face surfaces are inclined toward each other and one ofthe end surfaces is narrower than the other, said first and second brick being disposed one above the other to provide adjacent face surfaces, said first brick being disposed so that the narrow end is adjacent the working lining and said second brick being disposed so that the narrow end surface is adjacent the shell.

2. The vessel of claim 1, in which the first brick is the lowermost brick.

3. The vessel of claim 1, in which the side surfaces of the first and second brick are inclined toward each other.

4. The vessel of claim 1, in which the adjacent face surfaces of the first and second brick contain depressrons.

5. The vessel of claim 4, in which the depressions in said first brick are hemispherical.

6. The vessel of claim 4, in Which the depressions in said second brick are intersecting grooves.

References Cited UNITED STATES PATENTS 1,328,380 1/1920 Laird 26643 2,024,595 12/1935 Petit 26346 2,077,842 4/1937 Kuhl et al. 26346 X 2,281,200 4/1942 McLain 266-43 X FOREIGN PATENTS 184,197 12/1955 Austria.

I. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Asszlstant Examiner. 

1. IN AN OXYGEN CONVERTER VESSEL COMPRISING A METAL SHEEL HAVING A MOUTH AT ITS TOP, A SHELL PROTECTIVE LINING IN CONTACT WITH THE INSIDE SURFACE THEREOF AND A WORKING LINING, SAID VESSEL BEING COMPOSED OF THREE MAJOR ZONES, THE BOTTOM ZONE, THE BARREL ZONE AND THE CONE SECTION ZONE, THE BOTTOM ZONE BEING GENERALLY DISH-SHAPED AND OF UPWARDLY OPENING CONCAVE CONFIGURATION, THE BRICK IN SAID ZONE TERMINATING IN A KNUCKLE AREA, SAID KNUCKLE AREA BEING CHARACTERIZED BY A CURVATURE IN THE SHELL BRIDGING THE BOTTOM AND BARREL ZONES, THE BARREL ZONES EXTENDING FROM THE KNUCKLE AREA UPWARDLY TO THE CONE SECTION ZONE, THE CONE SECTION ZONE BEING OF DOWNWARDLY OPENING TRUNCATED CROSS SECTION CONFIGRUATION, THE IMPROVEMENT COMPRISING A SHELL PROTECTIVE LINING KNUCKLE AREA CONSTRUCTION CONSISTING OF FIRST AND SECOND BRICK HAVING OPPOSED FACE SURFACES, SIDE SURFACES AND END SURFACES IN WHICH THE FACE SURFACES, ARE INCLINED TOWARD EACH OTHER AND ONE OF THE END SURFACES IS NARROWER THAN THE OTHER, SAID FIRST AND SECOND BRICK BEING DISPOSED ONE ABOVE THE OTHER TO PROVIDE ADJACENT FACE SURFACES, SAID FIRST BRICK BEING DISPOSED SO THAT THE NARROW END IS ADJACENT THE WORKING LINING AND SAID SECOND JACK BEING DISPOSED SO THAT THE NARROW END THEREOF IS ADJACENT THE SHELL. 